The Hindsight Bar End Mirror uses custom convex glass formed to our own specification to give you the perfect balance between field of vision and image magnification. To reduce glare, the glass has an automotive quality mirror tinting. Rubber mounting helps the glass resist vibration. The lightweight but sturdy construction allows the Hindsight Mirror to be positioned for optimal viewing without concern of movement during high speed runs or excursions over rough roads.  - 6061-T6 Aluminium CNC Machined Billet Construction - Black Anodized - All stainless hardware - Fully modular assembly; all parts are replaceable - Extension elbow is reversible to allow for either left / right side use. - Will fit most handlebar/clip-ons with an outer diameter of a 7/8? (requires10mm (3/8?) of bare bar out board of the grip/throttle assembly) - Optional Billet internal Bar End Mirror Adapter Kit will allow internal mounting on virtually any handlebar/clip-on